Afforestation in Uruguayan grasslands: Effects on bird and mammal diversity at stand and landscape scales

Abstract

Brazeiro, A., Cravino, A., Fernández, P., Haretche, F. 2018. Afforestation in Uruguayan grasslands: Effects on bird and mammal diversity at stand and landscape scales. Ecosistemas 27(3):48-59. Doi.: 10.7818/ECOS.1508

The expansion of afforestation (Eucalypus spp and Pinus spp) in Uruguay reduces and fragments its main ecosystem, the grasslands. What are the consequences of this process for wildlife, at the stand and landscape scales? This is the main question addressed in this paper. In five forested (Eucalyptus) landscapes (3 km-radius), with afforestation percentages of 12.6 to 38.6%, we analyzed patterns of diversity and abundance of birdsand mammals. The different natural (forests, grasslands, wetlands) and anthropic (forest plantations) environments of the landscapes were sampled (11/2015-03/2017) using trap cameras (mean: 11 per environment) for mammals and the point count method (≥25 points per environment) for birds. Grassland substitution by afforestation reduced locally (i.e., stand) the richness and abundance of bird species (68 and 90% respectively) and mammals (33 and 22% respectively). Open-habitat specialists were the most affected, while some close-habitat specialist or generalist species were detected within forest plantations. Despite the significant effects detected at the local level, the overall species richness at the landscape scale did not decrease with the increase of afforestation area in the assessed gradient. However, the richness of open-habitat birds decreased with afforestation area in the landscape. These results suggest that the conservation of medium/large mammals and generalist and forest birds could be feasible in forested landscapes that maintain at least 60% of natural habitats. But a significant fraction (37%) of grassland birds could be lost, if conservation measures are not taken.